reporter: their uncle ruslan tsarni said he too saw changes in tamerlan. >> it was a different tamerlan. seeing no purpose in life but to pursue the path of god. okay. when i asked what is the path, he would say some kind of jihad. >> reporter: on his you-tube page last year, tamerlan endorsed several jihady videos. but what about dzhokhar, the younger brother? >> he's from chechnya. i said, whoa, so you were there during all the war the russia and all the bombing and all the terror. he said yeah but i don't remember it really. to tell you the truth i don't remember it. then he went on to say how grateful he was to be here and what a lucky and fortunate person he was. >> reporter: the uncle believes the younger brother was swayed by the older brother. >> the older brother involved him. dzhokhar would never ever have any idea. even by that age he wouldn't have that hatred intentionally to cause harm to innocent people. >> reporter: was he polite? very polite. very polite. >> reporter: on tuesday, a day after the marathon bombing, dzhokhar came to gilberto jr.'s auto body shop. what did h